Dual boot menu show to external DP, not show in Local DP after reboot.

Question

Hi,

We encounter an issue, when we installed 2 Windows 10 OS in one system,
and in cold boot, the dual boot menu work normal in Local DP screen.

Then after reboot, the dual boot menu will show to external DP port, even we not plug a external DP monitor, it will let us Local DP show a black screen, need to wait timeout seconds then show first OS login screen in Local DP.

It is Windows 10 known issue or Intel graphics driver issue?

Thanks & Regards.
USIGino

Answer 1

@ChiGino
Hi,
According to your description, this sounds like a graphics driver issue.
Which screen gets BIOS output during the boot process is up to the graphics card. Some graphics cards output to all displays simultaneously, some will only output to whichever port it considers to be "port 1".

Looks like every time you reboot the computer the primary display configuration would be lost. Display 2 would become primary and Display 1 would become secondary, right?
I think it could be a driver conflict.
You could try the following method:
Windows key + R
Type msconfig
Go to services tab
Check "Hide all Microsoft services"
Uncheck "Intel HD Graphics Control Panel Service" (or something similar) to disable the Intel driver
Click Apply then click OK

In some cases, you could check the device manager and find the display adapter, Roll Back Driver maybe also useful.

Hope above information can help you.

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Answer 2

@Jenny Feng Thanks.

1. We know it is Intel graphics driver issue, before install Intel graphics driver, no issue.
   After installed Intel graphics driver, issue can be duplicated, and disable Intel graphics driver from device manager, can avoid this issue.

We report to Intel, Intel replied that Intel do not support dual boot configuration.

2. At command prompt (Admin), enter the following command:
   bcdedit /set {bootmgr} displaybootmenu yes

Cold boot will still show GUI boot manager, then reboot will change to show text boot manager instead issue of show to external DP port, even we not plug a external DP monitor.

why this command setting will cover GUI boot manager to text boot manager?

Thanks & Regards.
USIGino